This is a nice antique 2.0 inch capacity C-Clamp with the cast steel design, has the threaded wing screw type adjusting rod.  This one is not marked by the maker, but in nice quality, nicely finished frame casting, and in great shape.  It's in very good usable condition with no rust, straight, not bent, good threaded rod. This type of C-Clamp is made of top quality steel and is heavy duty, so these could be used in metal working.